Composition and method to remove asbestos

ABSTRACT

A composition for transforming a chrysotile asbestos-containing material into a non-asbestos material is disclosed, wherein the composition comprises water, at least about 30% by weight of a boron tetrafluoride salt, free of or having only small amounts of an inorganic acid, an inorganic acid salt or a mixture thereof. A method of transforming the asbestos-containing material into a non-asbestos material using the present composition also is disclosed.

This invention was made with Government support under contractDE-AC02-76CH00016 awarded by the Department of Energy. The Governmenthas certain rights to this invention.

RELATED APPLICATIONS

This application is related to the following commonly assignedapplications, which have been filed simultaneously herewith and thedisclosures of which have been incorporated herein by reference in theirentirety:

(1) Ser. No. 08/721,854 filed Sep. 27, 1996, entitled COMPOSITION ANDMETHOD TO REMOVE ASBESTOS;

(2) Ser. No. 08/721,859 filed Sep. 27, 1996, entitled COMPOSITION ANDMETHOD TO REMOVE ASBESTOS;

(3) Ser. No. 08/721,856 filed Sep. 27, 1996, entitled COMPOSITION ANDMETHOD TO REMOVE ASBESTOS;

(4) Ser. No. 08/721,863 filed Sep. 27, 1996, entitled COMPOSITION ANDMETHOD TO REMOVE ASBESTOS;

(5) Ser. No. 08/721,857 filed Sep. 27, 1996, entitled FOAM COMPOSITIONFOR TREATING ASBESTOS-CONTAINING MATERIALS AND METHOD OF USING SAME; and

(6) Ser. No. 08/721,853, filed Sep. 27, 1996, entitled CORROSIONINHIBITING COMPOSITION FOR TREATING ASBESTOS CONTAINING MATERIALS.

BACKGROUND OF THE INVENTION

This invention relates to methods and compositions for digesting thechrysotile form of asbestos ( "chrysotile asbestos") into non-asbestosmaterial while the chrysotile asbestos is a component of agypsum-containing cementitious composite, and especially to methods andcompositions for the in-place digestion of chrysotile asbestos presentin composite material that is bonded to a support structure.

Chrysotile asbestos is a serpentine asbestos fibrous-like materialconsisting of alternating layers of silica and magnesium oxide/hydroxidebound to each other through covalently shared oxygen.

At least in part because of its availability and unique fire resistanceand thermal properties, chrysotile asbestos has been used commerciallyin a variety of building products, including, for example, fireresistant roofing shingles, acoustical plasters, fire resistant andthermally insulating coating compositions and the like. In the formationof fire resistant coating compositions, found to be appropriate fortreatment by the present invention, small amounts of chrysotile asbestoswere mixed with a settable bonding material, such as calcium sulfatehemihydrate, and, optionally, other materials such as vermiculite andthe like. The composition was then applied to a structure where it formsa hardened gypsum-containing coating. For example, such compositionsfound considerable use in multi-story buildings wherein thegypsum-containing composition was applied as an adherent coating tosteel girders, floor support plates, concrete decking and the like toprovide fire resistance and high-temperature thermal insulationproperties which aid in preventing damage and even possible collapse ofsuch buildings in the event of fire.

In recent years asbestos has been classified as a regulated material inthe United States. Federal, state and local government agencies havepromulgated regulations dealing with the use and disposal ofasbestos-containing building materials. The U.S. EnvironmentalProtection Agency ("EPA") has defined asbestos-containing material("ACM") as a material which contains greater than one percent (1%)asbestos. In accordance with regulatory procedures, various safeguardsare employed to protect workers from inhaling asbestos fibers duringremoval or demolition activities. Such safeguards include, among others,requiring workers to wear approved respirator or breathing apparatus, aswell as protective clothing, requiring any area in a building in whichasbestos-containing material is being removed to be isolated or enclosedfrom the remainder of the building, and requiring the enclosed work areato be kept at a negative pressure by the use of special apparatusequipped with HEPA filters to prevent airborne asbestos fibers fromleaving the work area. Such isolation of the work area is an expensiveand time consuming part of the process.

Generally, prior art methods for handling asbestos-containing buildingmaterials have taken several approaches. One approach has been tochemically alter asbestos fibers before using them in building products.This approach is discussed, for example, in U.S. Pat. Nos. 4,328,197 and4,401,636, both to Flowers, and in U.S. Pat. No. 4,474,742 to Graceffaet al.

Greceffa et al (U.S. Pat. No. 4,474,742) teach treatment of asbestoswith hydroxamic acid and iron chelating agents to remove the ironpresent in the asbestos based on the presumption that the iron is theharmful component. In the Flowers patents (U.S. Pat. No. 4,328,197 andU.S. Pat. No. 4,401,636), one is taught to contact asbestos fibers withan aqueous solution of a weak base/strong acid or a strong base/weakacid salt of manganese, chromium, cobalt, iron, copper or aluminum ormixtures thereof, to convert the asbestos fibers into a metal-micelleproduct. In general, the process contemplated by Flowers is effected bypreparing a slurry of asbestos fibers in an aqueous solution of theappropriate salt, effecting the conversion of the asbestos fibers tometal-micelle fibers in the slurry, and recovering the metal-micellefibers from the slurry for use in the subsequent preparation of thedesired fiber-containing end product.

Another approach is to treat previously formed asbestos-containingbuilding materials by encapsulating the materials to thereby prevent theasbestos fibers from becoming airborne. A resinous encapsulating coatingmaterial typically would be applied by spraying, brushing or troweling.Care must be taken when using encapsulating methods so as not tophysically damage the building material being encapsulated.Encapsulation is a containment method and, thus, the encapsulatedmaterial remains in place during the life of the building.

A number of removal techniques have been proposed, and each has itsadvantages and disadvantages. For example, it has been proposed tosimply scrape or chip away at dry untreated asbestos-containing materialand to collect the scrapings for discard. This technique, which isreferred to as dry removal, is generally considered unacceptable byregulatory agencies since it provides no safeguard against the releaseof airborne asbestos particles.

Dry vacuum methods have been attempted to overcome the problem of dryremoval by incorporating an exhaust filtering system to preventpollution to the outside environment and by using sealed containers forstoring and discarding the collected asbestos-containing material. Oneof the disadvantages of this dry vacuum method is that the bond betweenthe dry building material and the underlying surfaces on which it iscoated may be stronger than the vacuum capabilities of the equipment. Inthose cases, it is necessary to dislodge at least a portion of theasbestos-containing material by scraping or chipping, which has the samelimitations as the dry removal process described above.

Wet removal processes have been developed as a means for reducing theproblems associated with the various dry removal techniques. Wet removalgenerally involves wetting a building material with water orwater-surfactant solution to soften it and to thereby facilitate itsremoval. Wet removal clearly represents an improvement over dry removal.However, the use of water as a softening agent is not entirelysatisfactory because water penetrates slowly, does not completely wetmost building materials, and tends to run off the surfaces beingtreated.

Over the past several years, wet removal techniques have been improvedby devising more effective wetting and/or softening compositions. RecentU.S. patents which relate to such improved wet removal techniquesinclude, for example, U.S. Pat. No. 4,347,150 to Arpin; U.S. Pat. No.4,693,755 to Erziner; and U.S. Pat. No. 5,258,562 to Mirick et al.

The Arpin patent discloses a technique for wetting and removing friableinsulating materials from an underlying substrate using a two-partwetting system. The first component comprises an aqueous alkali metalsilicate dispersion blended with a cationic or nonionic surfactant andthe second component comprises a mixture of an acrylic latex containinga reagent that is reactive with the alkali metal silicates in the firstpart. The two parts are stored separately and are mixed shortly beforeuse to form a stripping composition which facilitates the removal of thebuilding material while encapsulating the individual asbestos fiberscontained therein. The removed material must be handled as anasbestos-containing material.

The Erzinger patent exemplifies a wet method for removingasbestos-containing materials from a substrate. This patent disclosesapplying a composition containing a cellulosic polymer to theasbestos-containing material, allowing the cellulosic polymer-containingcomposition time to penetrate and wet the asbestos-containing material,removing the wet material from the underlying substrate by mechanicalforces, and collecting the removed material for discard.

The Mirick et al patent is centered on the concept of removing asbestosfiber containing building material by applying a dilute aqueous solutionof an acid, which may include a separate source of fluoride ions such asan alkali metal or ammonium salt of hydrofluoric acid, to the buildingmaterial for the purpose of conditioning the material to aid in itsremoval while partially converting the asbestos fibers. The buildingmaterial, after having been treated with the dilute acid solution,preferably is removed for further treatment and/or discard. Mirick et alfurther contemplate that the wet building material, once removed, canthen be digested by immersing the material into a bath of an acidsolution, preferably with heating and agitation, until all of theasbestos material has been destroyed.

The problems of wet removal techniques include the requirements ofphysical removal and handling of the wet asbestos-containing material.In addition, the removed material must be further treated to destroy theremaining asbestos component if the material is to be discarded as anon-asbestos-containing material.

In the process described in Mirick et al, in which a combination of acidand fluoride source is used, the formed solution generates excessivehydrogen fluoride noxious gas while in storage and during applicationwhich presents a health hazard to the applicator. The Office of Safetyand Health Administration ("OSHA") has set an upper permissible exposurelimit of three (3) parts per million of hydrogen fluoride in theatmosphere.

While there have been improvements in the treatment and handling ofasbestos-containing building materials in recent years, the searchcontinues for still further improvements.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an improved composition fortransforming chrysotile asbestos to non-asbestos material.

It is another object of the invention to provide an improved compositionand method for treating gypsum-containing cementitious buildingmaterials which contain chrysotile asbestos to transform the buildingmaterials to non-asbestos materials (i.e., materials which contain lessthan 1% chrysotile asbestos), while they are part of the buildingenvironment and supported on an underlying substrate.

Another object is to treat a building material which contains gypsum,chrysotile asbestos and, optionally, other components, such as porousaggregate particulate as, for example, vermiculite, while part of abuilding structure, to transform the building material to anon-regulated material, without removing the building material from itsunderlying substrate and without substantially impairing the physicalintegrity and heat insulating properties of the building material.

Another object is to provide a treating composition which does notutilize any acid, or at most utilizes only very low concentration ofacid, yet which is capable of efficiently transforming chrysotileasbestos-containing building materials into non-asbestos materials,while the building materials are part of the building environment andsupported on an underlying substrate.

A still further object is to provide a treating composition which doesnot generate hydrogen fluoride gas in excess of present OSHA limitsduring storage and use.

In accordance with the invention, these and other objects and advantagesare achieved by the present composition and method for transformingchrysotile asbestos material to non-asbestos material. The compositioncomprises a unique combination of water, a high concentration of atleast one boron tetrafluoride salt of ammonia, an alkali metal oralkaline earth metal, and, optionally, a very low concentration (i.e.,from 0 up to about 5% by weight, based on the total weight of thecomposition) of an inorganic acid or acid salt. The present compositionis applied to the building materials in a manner which permitsabsorption of from about 8 to 20 parts by weight of treating compositionper part by weight of chrysotile asbestos contained in the materialbeing treated.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention is intended for the treatment of gypsum-containingcementitious materials which contain chrysotile asbestos fibers totransform the building materials to non-asbestos materials. The presentinvention is especially useful for decomposing chrysotile asbestosfibers contained in gypsum-based building materials that have beenpreviously applied to the structural components, such as steel beams,decking and the like of buildings as coatings thereon to provide fireand heat resistance thereto and to provide an asbestos free coatingwhich retains its integrity and its fire and heat resistance propertieson the substrate. Finally, the present invention provides a compositionwhich can decompose chrysotile asbestos fibers without generation ofnoxious hydrogen fluoride under storage and use conditions.

The present invention is directed to the use of a treating compositionwhich is an aqueous solution or dispersion of at least one borontetrafluoride salt of ammonia, an alkali metal or an alkaline earthmetal. The preferred salts are the alkali metal tetrafluooborates and,more specifically sodium tetrafluoroborate. The boron tetrafluoride saltshould be soluble in the aqueous treating compositions of the presentinvention in the amounts described hereinbelow. The boron tetrafluoridesalt component is employed in the present composition in highconcentrations of at least about 10%, preferably at least about 20% and,most preferably, at least about 30% by weight, based on the weight ofthe treating composition, up to the saturation point of the salt in theaqueous system.

The present composition preferably does not contain any added acidcomponent. However, an acid component may be added to the presentcomposition in an amount of up to about 7%, preferably up to about 5%,based on the weight of the composition. The acid component, whenpresent, can be selected from any inorganic acid or inorganic acid saltor mixtures thereof. The acid component should have a pKa of up to about2.5, and preferably up to about 2.2. Further, the acid component shouldbe highly soluble in water to form the present composition. Preferredinorganic acids include, for example, sulfuric acid, nitric acid,phosphoric acid, hydrochloric acid and mixtures of such acids. The mostpreferred acid is phosphoric acid. In addition, small amounts (up toabout 5%, preferably up to about 2% by weight of the acid component) canbe in the form of an organic acid. The preferred inorganic acid saltsare the half acid salts, as for example, ammonium and alkali metalbisulfates and the like. The preferred salts are the ammonium salts ofthe half acids.

It has unexpectedly been found that by employing high concentrations ofat least one boron tetrafluoride salt with no added acid (or at mostvery low amounts of acid) the treating compositions of the presentinvention can be stored and used to transform chrysotileasbestos-containing building materials to non-asbestos materials whilein place in a building environment without generating noxious hydrogenfluoride gas in amounts which are unacceptable for commercialapplication, as exemplified by OSHA standards. This represents a majorimprovement over prior art asbestos treating compositions which rapidlygenerate large quantities of hydrogen fluoride gas when used, thuscreating a dangerous work area. It has also been found that becausethere is little if any acid added to the present treating compositions,the present compositions are much less corrosive than prior artcompositions.

The present treating compositions are particularly useful for treatingbuilding materials which contain gypsum in addition to chrysotileasbestos, since their use results in the transformation of thechrysotile asbestos containing material to a non-asbestos material(i.e., a non-regulated material containing less than 1% by weightasbestos) while permitting the building material to remain in place aspart of the building structure.

It is believed, though not meant to be a limitation on the presentinvention, that when the composition of the present invention contactschrysotile asbestos, the tetrafluoraborate salt, when in contact withthe chrysotile asbestos material, generates a minute amount of hydrogenfluoride which is immediately consumed by reaction with silicon atoms ofthe chrysotile asbestos contained in the material being treated. Thisreaction further generates hydrogen fluoride at a rate which permitsimmediate reaction with additional silicon atoms until essentially allof the chrysotile is transformed to a non-regulated material andessentially no hydrogen fluoride gas is lost to the atmosphere. It hasbeen unexpectedly found that the present compositions do not producehydrogen fluoride in excessive amounts while in storage nor directly orindirectly cause generation and expelling of HF gas when in contact withchrysotile asbestos.

The present treatment composition may be readily applied to chrysotileasbestos containing cementitious coatings in any manner so that fromabout 8 to 20 parts by weight, preferably 9 to 15 parts by weight, ofthe aqueous treating composition is applied per part by weight of thechrysotile asbestos in the material being treated. The amount to beapplied will depend on the amount of chrysotile asbestos initiallypresent in the material, the concentration of the boron tetrafluoridesalt and acid, if any, in the treating composition, and the thicknessand absorptive capacity of the material being treated. The exact amountcan be readily determined by small scale application and testing.

When further occupancy of the building or treated area is planned, eventhough the present treating composition is significantly less corrosivethan prior art compositions, it is typical to add agents to the presentcomposition which will inhibit the corrosion of metallic substratematerials (e.g. steel beams, galvanized corrugated decking, steel pipesand the like) to which the material being treated is attached and/or invicinity thereof. It has been found that certain specific materials areuseful as corrosion inhibiting agents for a broad spectrum of metalswhen part of the present treating composition. These agents, and theirincorporation in treating compositions described herein which decomposechrysotile asbestos into a non-asbestos material and the utilization ofsuch treating compositions to transform the asbestos-containingcementitious material to a non-regulated material are fully described ina concurrently filed, copending application, U.S. Ser. No. 08/721,853,filed Sep. 27, 1996, entitled CORROSION INHIBITING COMPOSITION FORTREATING ASBESTOS CONTAINING MATERIALS, the disclosure of which isincorporated herein in its entirety by reference.

The method of the present invention transforms chrysotileasbestos-containing material into a material which contains very little,if any, chrysotile asbestos when measured, for example, by polarizinglight microscopy, X-ray diffraction, or other conventional method. Theresultant treated material contains less than one percent (1%), andnormally less than one-half of one percent (0.5%) chrysotile asbestos inthe overall structure of the resultant material. Thus, the materialtreated by the present composition results in a product which meets theU.S. governmental standards of a non-regulated asbestos-free materialwhich may be safely handled by ordinary means. Further, it has beenunexpectedly found that the present composition and method provides thistransformation without causing a degradation of the cementitiousmaterial and, thereby, permits the material to remain in place and tocontinue to provide the functions of fire resistance, etc. for which itwas initially installed.

The chrysotile asbestos contained in the cementitious material issubstantially completely transformed to a non-asbestos product while inplace and part of the cementitious material. Typically, at least abouteighty five percent, and preferably at least about ninety percent, ofthe chrysotile fibers are decomposed by the present composition andmethod to provide a non-regulated safe product without degradation ofthe cementitious material and, thereby, not requiring removal of thematerial nor detracting from the properties of the cementious coatingmaterial.

All that is necessary to achieve the decomposition of the chrysotileasbestos fibers in accordance with the present invention is to wet thematerial containing the chrysotile fibers with the treating composition,for example, by spraying or brushing the material with the treatingcomposition. In the case of asbestos-containing building materials, suchas fireproofing materials coated on girders, beams and floor supportplates, this can be done by spraying the treating composition in theform of a solution, dispersion, gel or foam (e.g., a foam which isstable for at least about 1 minute, and preferably for at least about 60minutes) directly onto the asbestos-containing material, preferablywhile it is in place in the building environment. It is unnecessary todisturb the asbestos-containing materials since the treatingcompositions typically will penetrate into the building materials andcontact the asbestos fibers contained therein. In those cases where itis desirable to increase the rate of penetration of the treatingcomposition into the building material, one or more wetting agents maybe added to the treating composition. For example, an anionicsurfactant, such as linear alkyl sulfonates, sodium lauryl sulfates,polyalkoxy carboxylates, or a non-ionic surfactant, such as alcoholalkoxylates, alkyl phenol ethoxylates, polyoxyethylene esters andpolyalkylene oxide block copolymers, can be added to the treatingcomposition in conventional amounts, e.g., in amounts of up to about 5%by weight based on the total weight of the composition, to increase therate of penetration of the treating composition into the buildingmaterial and the resultant wetting of the asbestos fibers. Excellentwetting has been achieved in most cases, however, with the treatingcomposition alone, without additional wetting agents.

The present treating composition should be applied to thegypsum-containing cementitious building material in manners which permita total application of from about 100 to 200% by weight, preferably fromabout 125 to about 175% by weight, of the subject composition based onthe weight of the cementitious building material. The exact amount willdepend on the concentration of the chrysotile asbestos contained in thebuilding material being treated.

Because of the high concentration of boron tetrafluoride salt in thetreating compositions of the invention, the desired asbestostransformation may be achieved by a single application of the treatingcomposition on the building material while it is in place in thebuilding environment. However, in some cases it may be necessary ordesirable to make successive applications, preferably without anyintermediate drying step, until the desired degree of digestion of thechrysotile asbestos fibers is achieved.

The preferred manner of applying the subject treating composition to thematerial is by applying the composition in the form of a foam directlyonto the major free surface(s) of the building material. As the materialto be treated is in the form of a coating on a substrate buildingcomponent, usually one major surface is exposed and free for applicationof the subject composition. Spraying of the aqueous treating compositionmay require successive applications, preferably without any intermediatedrying step(s) between applications. Application of a foamed aqueoustreating composition provides an extended contact time and apseudo-encapsulation of the material being treated while thetransformation is occurring. The formation of the foamed composition andits specific utilization in the instant method of transformingchrysotile asbestos-containing building materials to non-asbestosmaterials is fully described in concurrently filed, copending U.S.application Ser. No. 08/721,857, filed Sep. 27, 1996, entitled FOAMCOMPOSITION FOR TREATING ASBESTOS-CONTAINING MATERIALS AND METHOD OFUSING SAME, the disclosure of which is incorporated herein by reference.

It has been found that when a chrysotile asbestos-containing material istransformed in place in accordance with the present invention, thephysical integrity and adherence of the resulting non-asbestos materialto the underlying substrate are such that it may be left in place toperform the fireproofing or other function for which theasbestos-containing material was originally installed. The resultantmaterial subsequently may be treated by spraying or the like with wateror with a mild alkaline solution, such as sodium bicarbonate, calciumcarbonate, sodium carbonate, magnesium hydroxide or the like in order toneutralize any acid that might be present in the material.

Even though it has been found that building materials which have beentreated in place with the present treating compositions to transform anyasbestos contained therein to non-asbestos material essentially maintaintheir physical integrity and adherence to the underlying substrate,there are cases when it is necessary or desirable to strengthen thematerial or its adherence to the substrate. This can be accomplished byapplying a polymeric binding agent to the material, either before thebuilding material has been initially wet with the treating compositionor after the building material has been treated and/or rinsed and/orneutralized as described above.

The method of the invention, as applied to the abatement of asbestos inbuildings, may typically include the step of removing any obstructions,such as interior partitions, ceilings and column covers, to expose theasbestos-containing material to be treated. This will enable thesampling and testing of the material to determine its composition andother relevant characteristics, thereby facilitating the selection of anoptimum asbestos treatment composition and treatment procedure inaccordance with the present invention. The treatment composition is thenapplied directly to the asbestos-containing material while in place inamounts described above to provide a non-regulated material. Theresultant material may be further treated with water and/or aneutralizing agent.

One of the advantages of the invention is that it enables buildingmaterials to be treated in place without destroying their physicalintegrity and adherence to their substrate such that the materials maybe left in place to perform their originally intended function after theasbestos containing material has been transformed to non-asbestosmaterial.

The following examples are intended to illustrate the invention withoutimposing limits on the scope of the invention, as defined by the claimsappended hereto. All parts and percentages are by weight unlessotherwise indicated.

EXAMPLE 1

Several solutions of sodium tetrafluoroborate (NaBF₄) were prepared bymixing the indicated amount of sodium tetrafluoroborate with water, asindicated in Table I below. These solutions were added to a simulatedfireproofing material which contained 0.7 parts chrysotile asbestos, 1.5parts vermiculite and 3.8 parts of gypsum. The respective solutions wereallowed to remain in contact with the simulated fireproofing materialfor seven days (without stirring) in a closed plastic container. Afterseven days, the mixtures were filtered, washed with water, dried andanalyzed for chrysotile asbestos by X-ray diffraction. The compositionof the various solutions and the results of the analyses are shown inTable 1.

                                      TABLE 1                                     __________________________________________________________________________    NaBF.sub.4 (parts)                                                                   H.sub.2 O (parts)                                                                   pH (initial)                                                                        pH (after 7 days)                                                                     Residual Chrysotile (%)                            __________________________________________________________________________    4.6    4.4   2.6   2.7     0.65                                               4.0    5.0   2.5   2.6     0.76                                               __________________________________________________________________________

The results show that chrysotile asbestos decomposition was achievedusing an acid-free treating solution of the present invention and theresultant product was a non-regulated product having a residualchrysotile content of under 1%.

EXAMPLE 2

Example 1 was repeated except that the treating solution and thesimulated fireproofing material was permitted to remain in contact foreleven days instead of seven days. The results of this Example are shownin Table 2.

                                      TABLE 2                                     __________________________________________________________________________    NaBF.sub.4 (parts)                                                                   H.sub.2 O (parts)                                                                   pH (initial)                                                                        pH (after 11 days)                                                                    Residual Chrysotile (%)                            __________________________________________________________________________    4.6    4.4   2.6   2.6     >0.2                                               __________________________________________________________________________

The resultant product was a non-asbestos material which retained itsphysical integrity.

What is claimed is:
 1. A method of treating a building materialcontaining chrysotile asbestos, wherein said building material has beenapplied to a substrate in a building, comprising:(a) providing anadmixture composition derived from admixing (i) water, (ii) at leastabout 10% by weight of at least one alkali metal, alkaline earth metalor ammonium tetrafluoroborate salt, and (iii) up to about 7% by weightof an inorganic acid, an inorganic acid salt or mixtures thereof; (b)applying said admixture composition to the chrysotileasbestos-containing building material; and (c) permitting said admixturecomposition to remain in contact with the building material for asufficient period of time to reduce the amount of chrysotile asbestoscontained therein to less than 1% by weight of the treated material. 2.The method of claim 1, wherein the building material is agypsum-containing cementitious building material.
 3. The method of claim1, wherein said composition is applied in the form of a foam.
 4. Themethod of claim 1, wherein said composition further contains a metalcorrosion inhibiting agent.
 5. The method of claim 1, wherein thetetrafluoroborate salt is present in a concentration of at least about30 weight percent and is selected from the group consisting of ammonium,alkali metal and alkaline earth metal tetrafluoroborates and mixturesthereof.
 6. The method of claim 2 or 5, wherein said composition furthercontains a component capable of inhibiting corrosion of metals incontact therewith.
 7. The method of claim 1, 2, 3, 4 or 5, wherein saidcomposition is applied to the building material in an amount of fromabout 8 to about 20 parts by weight based on the weight of chrysotileasbestos contained in the building material being treated.
 8. Acomposition capable of transforming an asbestos-containing material to amaterial containing less than 1% by weight of chrysotile asbestos,comprising a mixture of (a) water, (b) at least one alkali metal,alkaline earth metal or ammonium tetrafluoroborate salt, and (c) up toabout 7% by weight, based on the weight of the composition, of aninorganic acid, an inorganic acid salt or mixture thereof, wherein thetetrafluoroborate salt is present in a concentration of from at leastabout 10 weight percent of the composition.
 9. A composition capable oftransforming an asbestos-containing material to a material containingless than 1% by weight of chrysotile asbestos derived from admixing (a)water, (b) at least one alkali metal, alkaline earth metal or ammoniumtetrafluoroborate salt, and (c) an inorganic acid, an inorganic acidsalt or mixture thereof, wherein the tetrafluoroborate salt is added ata concentration of from at least about 10 weight percent of thecomposition, the acid component (c) is added at a concentration of up toabout 7% by weight, based on the weight of the composition and said acidcomponent (c) has a pKa of up to about 2.5.
 10. The composition of claim8 or 9, wherein the tetrafluoroborate salt is an alkali metaltetrafluoroborate.
 11. The composition of claim 8 or 9, which issubstantially free of acid.
 12. The composition of claim 8 or 9, whereinthe acid component (c) is present in a concentration of up to about 5%by weight.
 13. The composition of claim 8 or 9, wherein thetetrafluoroborate salt is present in a concentration of at least about30 wt percent based on the weight of the composition.
 14. Thecomposition of claim 8 or 9, wherein said mixture further contains acomponent capable of inhibiting corrosion of metals in contacttherewith.
 15. The composition of claim 8 or 9, wherein said mixturefurther contains a component capable of causing said composition to bein the form of a foam which is stable for at least about 1 minute. 16.The composition of claim 10, wherein said mixture further contains acomponent capable of inhibiting corrosion of metals in contacttherewith.
 17. The composition of claim 10, wherein said mixture furthercontains a component capable of causing said composition to be in theform of a foam which is stable for at least about 1 minute.
 18. Acementitious product adhered to a building substrate suitable forproviding fireproofing properties to said substrate formed by the methodcomprising:(a) applying, to a cementitious composition comprising ahydrated cement, porous aggregate particulate and chrysotile asbestos,an admixture composition derived from admixing (i) water, (ii) at leastabout 10% by weight of at least one tetrafluoroborate salt of ammonium,alkali metal, alkaline earth metal or mixtures thereof, and (iii) up toabout 7% by weight of an inorganic acid, an inorganic acid salt ormixtures thereof; (b) permitting said admixture composition to penetratethe cementitious composition and contact the chrysotile asbestoscontained therein; and (c) allowing said admixture composition to remainin contact with the cementitious composition for a sufficient period oftime to provide a cementitious product having less than 1% by weight ofchrysotile asbestos based on the weight of the product adhered to thebuilding substrate.
 19. The product of claim 18, wherein saidcomposition is applied in the form of a foam.
 20. The product of claim18, wherein the particulate is vermiculite.
 21. The product of claim 18,19 or 20, wherein said admixture composition is applied to thecementitious composition in an amount of from about 8 to about 20 partsby weight based on the weight of chrysotile asbestos contained in thebuilding material being treated.